The main enemy of helicopters flying 500 feet or below in altitude are what is referred as B1RDs, birds. Depending on the size of the B1RD it can take out a helicopters tail rotor, or even break through the windshield.
One grey day during the migration of ducks in South Louisiana I was flying solo to pick up some passengers in the west Delta area of the Gulf of Mexico, when suddenly appeared a large flock of duck in front of me. As I was trying to steer clear clear of then, I heard a loud CRASH. Pieces of plexiglass where hitting my left side. I looked to my left and in the seat next to me, there was a dead duck (no pun intended). Feathers where everywhere with the cold winter wind rushing through the large whole in the windshield. I counted my blessings that he came in through the other side and not on my side. If the duck had. you would not be reading this story.
Don’t forget to check out my Science Fiction four book series: A Saga of Dogs of War-A Story of Mercenaries. Paperback is available on Amazon at https://www.amazon.com/-/e/B08JQRR122 My eBooks are available at Books2Read at https://books2read.com/u/4Dglpg in all formats. They make great gifts for only .99 cents each.